Add an interface to gather text surrounding the selection.

content/public/browser/android/content_view_core.h

Index: content/public/browser/android/content_view_core.h
diff --git a/content/public/browser/android/content_view_core.h b/content/public/browser/android/content_view_core.h
index 1501985b8a53bfa15439eb84ada178e1b8f34d63..723a4bfcf5fa5198a7208a333deeed8dea284e41 100644
--- a/content/public/browser/android/content_view_core.h
+++ b/content/public/browser/android/content_view_core.h
@@ -10,6 +10,7 @@
 #include "base/android/scoped_java_ref.h"
 #include "base/callback.h"
 #include "content/common/content_export.h"
+#include "content/public/browser/android/text_surroundings_delegate.h"
 #include "content/public/browser/navigation_controller.h"
 #include "ui/gfx/rect.h"
 
@@ -68,6 +69,15 @@ class CONTENT_EXPORT ContentViewCore {
       const gfx::Vector2dF& scroll_offset,
       float page_scale_factor)> UpdateFrameInfoCallback;
 
+  // Text surrounding selection.
+  typedef base::Callback<void(const base::string16& content,
+                              int start_offset,
+                              int end_offset)>
+      TextSurroundingSelectionCallback;
+  virtual void RequestTextSurroundingSelection(
+      int max_length,
+      const TextSurroundingSelectionCallback& callback) = 0;
+
  protected:
   virtual ~ContentViewCore() {};
 };